摘要 |
PURPOSE:To enable to form a marking groove with a step difference required for alignment without augmenting the layer resistance in a high concentration diffusion region by a method wherein a pattern in a marking region is formed by means of exclusive photoetching process independent of the photoetching process to form a pattern in the high concentration diffusion region. CONSTITUTION:A silicon substrate 1 is etched by means of conventional photoetching process utilizing photoresist material 2 as a mask to form a mark ing groove 3 into the P-type silicon substrate 1. Next a thermal oxide film 4 at 7,000 Kt is formed on the silicon substrate 1 and then a window is opened i a region to form a buried layer therein for N-type high concentration diffusion. Finally the oxide film 4 is removed to form an epitaxial layer layer without performing any unnecessary oxidation in the diffused region 5. |